Safety retainer for collared chisels in chipping hammers

ABSTRACT

This disclosure relates to a retainer for the reciprocating chisel of a chipping hammer, constructed as a flexible sling secured to the end of the hammer barrel and embracing the chisel adjacent to a collar on the chisel shank.

8 United States Patent 11 1 1111 3,781,023 Boyd Dec. 25, 1973 [54] SAFETY RETAINER FOR COLLARED' 3,345,079 10/1967 Wickham 279/l9.6

CHISELS IN CHIPPING HAMMERS 2,502,388 3/1950 Muller 2,830,792 4/1958 Sears [76] Inventor: James C. Boyd, c/o Tool Sales & 1,164,560 12 1915 Weiner 279 19 x S C 1137 El Tgwnship 6:53 :32 FOREIGN PATENTS OR APPLICATIONS County, Pa 15112 324,558 8/1920 Germany 279/l9.6

[22] Filed: July 1972 Primary Examiner-Travis S. McGehee [21] Appl. No; 272,783 Assistant ExaminerZ. R. Bilinsky Attorney-Wm. Henry Venable [52] US. Cl. 279/19.6 51 11m. 01 825d 17/10 [57] ABSTRACT [58] Field of Search 279/ 19.6, 19, 19.1, Thi i closur relates to a retainer for he reciproca 279/l9.2, 19.3, 19.4, 19.5, 19.7; 408/710 ing chisel ofa chipping hammer, constructed as a flexible sling secured to the end of the hammer barrel and [56] References Cited embracing the chisel adjacent to a collar on the chisel UNITED STATES PATENTS Shankl,920,765 8/1933 Rasch 279/19.6 X 2 Claims, 7 Drawing Figures SAFETY RETAINER FOR COLLARED CHISELS IN CHIPPING HAMMERS BRIEF SUMMARY OF THE INVENTION The object of this invention is to provide a safety retainer for chipping hammer chisels which is simple, light in weight, economical in cost, has a long life, and facilitates easy removal and entry of chisels. My safety retainer is in the form of a sling adapted to be secured to the end of a chipping hammer tool barrel. This sling extends forwardly from the barrel on two sides, at the forward end of which it is formed into a loop through which the chisel reciprocates in service. The chisel is provided with a collar and the forward loop of the sling is smaller than this collar, thus retaining the chisel so that it cannot fly out in case the shank thereof passes out of the holder.

BRIEF DESCRIPTION OF DRAWINGS An embodiment of my invention is illustrated in the accompanying drawings, in which,

FIG. 1 shows my tool retaining attachment applied to a chipping hammer with the chisel being held in retaining position.

FIG. 2 is a side view of a chipping hammer body with attached retainer showing how a chisel is inserted or removed from the hammer.

FIG. 3 is a view of a hammer and retainer similar to FIG. 2 after the tool has been inserted therein.

FIGS. 4 and 5 are plan and side views of my retainer ready for attachment to the hammer. 1

FIG. 6 shows the splicing sleeve used in assembling the chisel retainer, (a) being a side view and (b) being an end view thereof.

FIG. 7 is a diagram of such a sling made of two wire rope sections.

DETAILED DESCRIPTION For chipping castings removed from the molds in foundries, it is common practice to use a chipping hammer barrel 10 with a chisel 11. Until recently no retainer for the chisels has been required and the chisel 11 was a plain one without any collar such as collar 12 in the annexed drawings.

Federal regulations now require that all pneumatic chipping hammers have a retainer to prevent accidental ejection of the chisel. For this purpose a collar such as the collar 12 is provided on the chisel and various conventional retainers have been proposed. The object of my invention is to provide a retainer which has none of the disadvantages of those which have been heretofore proposed. The conventional retainer weighs from 2 to 3 pounds, adds to the length of the hammer, and requires longer chisels. My retainer weighs but two ounces, the present length chisels are easily and quickly inserted when it is used, and it is much less expensive than conventional retainers. The avoidance of increased weight alone, which the operator must carry, increases the operator's efficiency in his work.

In the annexed drawings, the collar 12 on the shank of the chisel 11 is illustrated as a round, circumferential collar, but the circular contour is not essential and the outline of the circumferential collar may be a polygon (e.g., square or hexagonal), a star shape, or any other shape, the circular form being preferable merely because of its simplicity.

' which are shown in FIG. 6.

The sling may be constructed of two sections of cable as illustrated diagrammatically in FIG. 7. These are a long section 16, the two ends of which are doubled back between a pair of crimps 15 to form one of the loops 14, and a short section 17 spliced to the long section 16 by a pair of crimps 15 to form the other loop.

For attachment of the sling to the pneumatic tool barrel 10, a circular groove 18 is machined around the end 19 of the hammer barrel. The width and depth of this groove is made to neatly and tightly receive one of the loops 14 of the sling 13. The sling is installed by driving the loop 14 into the groove 18, by placing a two-pronged fork over the splicing sleeves 15 and driving that loop 14 snugly into the groove 18 by hitting the fork with a hammer.

The loop 14 on the opposite side of the oval sling 13 is made large enough to permit the end of a chisel 11 to slip through it easily, but smaller than the collar 12 so that the tool 11 will not pass out of the sling.

The total length of the oval of the sling is made sufficient, with respect to the chisel shank, that when the shoulder 12 is against the loop of the sling in extended position as shown by solid lines in FIG. 2, the end of the shank slightly clears the mouth of the pneumatic tool holder 10.

To insert a tool into the hammer, it is first slipped through the loop 14 of the sling from the side as shown in dotted lines in FIG. 2. The chisel is then aligned with the barrel 10 as shown in solid lines and entered into the open mouth of the barrel 10. The wire cable of the sling, being elastic, tends to retract from the extended position shown in FIG. 2 and such spring-like action retains the chisel 11 in the hammer. Should the shank of the chisel 11 fly beyond the end 19 of the hammer barrel 10 in service, the collar 12 is caught by the loop of the sling so that it cannot accidentally fly out, but is safely retained thereby.

I claim:

1. A tool retainer for shouldered chisels in chipping hammers comprising a sling, said sling having (I) a closed loop adapted to fit tightly into a circular, circumferential groove on the hammer tool holder whereby the sling is secured thereto, (2) a closed loop adapted to permit the chisel to reciprocate therethrough in service but smaller in circumference than the outside circumference of the chisel shoulder, (3) two sections tangentially connecting the said loops together on each side and (4) connecting means between said loops and said two sections in the form of splicing sleeves adapted to be driven to tighten said loops.

2. A tool retainer for shouldered chisels in chipping hammers comprising a sling, said sling having (1) a loop of wire rope adapted to fit into a circumferential groove on the hammer tool holder, (2) a loop of wire rope adapted to permit the chisel shank to reciprocate therethrough but smaller than the outside diameter of the chisel shoulder, and (3) two wire rope sections tangentially connecting said loops together on each side. 1 

1. A tool retainer for shouldered chisels in chipping hammers comprising a sling, said sling having (1) a closed loop adapted to fit tightly into a circular, circumferential groove on the hammer tool holder whereby the sling is secured thereto, (2) a closed loop adapted to permit the chisel to reciprocate therethrough in service but smaller in circumference than the outside circumference of the chisel shoulder, (3) two sections tangentially connecting the said loops together on each side and (4) connecting means between said loops and said two sections in the form of splicing sleeves adapted to be driven to tighten said loops.
 2. A tool retainer for shouldered chisels in chipping hammers comprising a sling, said sling having (1) a loop of wire rope adapted to fit into a circumferential groove on the hammer tool holder, (2) a loop of wire rope adapted to permit the chisel shank to reciprocate therethrough but smaller than the outside diameter of the chisel shoulder, and (3) two wire rope sections tangentially connecting said loops together on each side. 